Method and system for secure information distribution based on group shared key

Abstract

Disclosed is a system and a method for information distribution. The system comprises: a server for generating a group key and its corresponding key deriving parameter, wherein the server encrypts sensitive contents by using the group key to obtain encrypted information; and terminals configured to receive the encrypted information through an open channel, extract the group key, then decrypt the encrypted information by using the group key to obtain the original content. In the group forming process, each terminal encrypts its private identifier using the public key and submits the ciphertext to the server. In information distribution process, the server transmits the ciphertext of sensitive contents and the key deriving parameter to the terminals via open channel Because private information available only to respective group members is required for calculating the group key, this mechanism ensures that the sensitive content can be transmitted securely on the open channel.